The present invention relates to filters. More particularly, the present invention concerns a process and an arrangement for filtering a contaminated medium by a brush filter.
It is known in the prior art (see German Offenlegungsschrift 27 45 526) to filter a contaminated medium (i.e., liquid or gas) by means of a fiber material. The fiber material (i.e., a plurality of fibers) may be fixed, at one side thereof, on a plate having a plurality of holes, on a tube, etc. During the filtration process the contaminated medium is introduced into a filter housing in a direction towards and against the support (i.e. plate, tube, etc.) of the fibers. The fibers thereby become compressed together and compacted against the support to form a filter bed. In order to clean the fiber material a cleaning medium back-flushes the fibers so as to straighten them out in a direction opposite to that of the flow of the contaminated medium. During the back-flushing any filter cake accumulated on the filter bed is removed therefrom and the filter can then be re-used.
It has been recognized that this construction is not satisfactory, since the compressed fibers are too compact to be satisfactorily backflushed and cleaned of the accumulated filter cake. Obviously, this disadvantageous feature adversely affects the effectiveness of such a brush filter, since it is difficult to clean.